Power transmission



Jan. 10, 1950 A. ZWALD 2,494,222

POWER TRANSMISSION Filed July 24, 1945 I 2 Shets-Sheet 1 Fig. 2.

6' TTU /vza Jan. 10, 1950 A. ZWALD I 2,494,222

' POWER TRANSMISSION Filed July 24, 1945 2 sheets-sheet 2 /7 7- TU A/EPatented Jan. 10, 1950 POWER TRANSMISSION Adolph Zwald, Portland, reg.,assignor to Hyster Company, Portland, 0reg., a corporation of OregonApplication July 24, 1945, Serial No. 606,834

2 Claims.

- This invention relates to improvements in power transmission gearing,and has particular reference to a novel control device for changing thegear ratio of the transmission.

The object of the invention, in general, is to provide an improvedsingle lever control to coordinate properly the operation of a pluralityof clutches or other devices for changing the gear ratio in atransmission.

A particular object of the invention is to provide a single levercontrol having a central neutral position and being movable in oppositedirections therefrom to engage one or the other of a pair of clutcheseffective to establish either a low or a high gear drivein thetransmission.

In accomplishing the above objects, a further object is to provide anovel rotatable shifter quadrant having a plurality of diagonal guidemeans for coordinately moving different shifting members to change thetransmission ratio in accordance with movements of the shifter quadrant.

With the foregoing and other objects in view, the invention resides inthe combination of parts and in the details of construction hereinafterset forth in the following specification and appended claims, apreferred embodiment thereof being illustrated in the accompanyingdrawings, in which:

Figure 1 is a view in rear elevationof my novel shifter quadrant andassociated levers for controlling the transmission,

Figure 2 is a view drawn to a smaller scale at right angles to Figure l,partly in elevation and partly in section, showing the linkage betweenthe shifter quadrant and instrumentalities in the transmission, and

Figure 3 shows the power transmission to which the invention is applied,being a continuation on a smaller scale of the view shown in Figure 1.

Referring first to Figures 1 and 2, the numeral It indicates a controlpedestal mounted conveniently for the operator of the power transmissiondevice. Pedestal IG carries a head bracket ll having a shaft l2pivotally mounting a cylindrical shifter quadrant I3. The quadrant l3may be manipulated by a handle I4 for rotation in opposite directionsfrom a neutral position, as indicated by the arrows in Figure 2, aresilient ball detent l5 being arranged to cooperate with a depressionin the shaft l2 to index the quadrant in the neutral position.

The shifter quadrant l3 transmits control functions by means of twoslots l6 and I1 having ends l8 and 2!, respectively, directed at rightangles to the shaft l2, and having ends 59 and 20, respectively,directed angularly with respect to the ends l8 and 2!. Slots [6 and i1guide the movements of cam followers 22 on the upper ends of levers 23and 24, pivotally mounted at 25 and 25 on the stationary head bracketII. The lever 23 constitutes a low clutch lever, being pivotallyconnected at its lower end with a low clutch link 21, and the lever 22constitutes a high clutch lever, being pivotally connected at its lowerend with a high clutch link 28. The low clutch link 21 ispivotallyconnected with a lever 30 having a supporting pivot 3| at itsmid-portion, and having pivotal connection at its lower end with a bellcrank 32. The bell crank 32 is journaled in a stationary supportingbracket 33 and is rigidly connected with a shifter yoke 34 which iseffective to engage and disengage a multiple disc clutch 35.

The high clutch link 28 is pivotally connected with a bell crank arm 40on a shaft 41 carrying a shifter yoke 42. The shifter yoke 42 isoperative to engage and disengage a multiple disc clutch 45. Thenumerals 46 and 41 indicate length adjustments in the links 21 and 28.

In the transmission (Figure 3), the bevel gear 50 is on the powertake-off shaft from a prime mover source of power. Asecond bevel gear 5!meshes with the gear 50 and is keyed on the shaft 52 so that the latteris constantly rotating in bearings 53 and 54 as long as the prime moveris operating. The clutches 35 and 45 include multiple disc assemblieshaving one set of plates rotatable with the shaft 52, and another set ofplates rotatable with external shells 55 and 56. The shell 55 is mountedon a small gear 51 and the shell 56 is mounted on a larger gear 58, andeach of these gears is carriedon bearings 59 for free rotation on theshaft 52. When the clutches are disengaged the shaft 52 rotates in thebearings 59 without producing rotation of gears 57 and 58.

A shaft 60 mounted in bearings 6| and 62 carries gears 63 and 64 splinedthereto and constantly in mesh with the previousl mentioned gears 51 and58. The shaft 60 drives through a second gear changing transmission,indicated generally by the reference numeral 65, to deliver power to apair of gears 65 and 61 on the device to be operated.

It will be observed from the foregoing description that the clutches 35and 45 are operative to provide two different transmission ratios forrotation in the same direction, and to provide a neutral or non-rotatingcondition. When both clutches are disengaged, both the gears 51 and 58will be disconnected from the rotating shaft 52, thereby alsodisconnecting the transmission unit 65 and the power output gears 66 andB1. The condition where both clutches are disengaged is that illustratedin the drawings wherein the cam followers 22 on the high and low clutchlevers: rest in theiiiid portionsof theslots' i6 and il'inthe shifterquadrant. It is noted that the ar rangement of the slots is such that inthis posi'-'-- tion both cam followers 22 he in the slot'portions l6 and2| at right angles to the shaft [2.

If the control lever I4 is moved to the left, as"

viewed in Figure 2, the high clutch lever will he held in neutralposition and the low clutch lever 23 will be rotated counterclockwise,as viewed in Figure 1, to engage the clutch 35. This establishes a lowdriving ratio through the small gear 51 to rotate the gears 66 and 61 atlow speed.

When th'e'lever itismoved in 'a' -clockwise directionasvieWedin FigureZ, the lbw-clutch lever 23 will be maintained irineutral position asshown in' Figurel to maintain' the clutch 35 disengaged. The high clutchlever 24 willthen be rotated counterclockwise; as viewed in Figure 1, toengage the clutch 4-5 and producerotation o -the gear 58. This-gearheinglarger than the gear 51, the shaft 6'0 and the gears EB and 'BT willthen be rotated in high g'e'ar' drive.

Thepresent arrangement provides for rapid shifting when necessarygthe'clutches absorbing the shocks resulting from quick changes so as to'prolongthe'life 'of the tiarisniis's'ion. This transmission-isparticularly designed fora drum yarder mountedo'ir a tractorforheavy-duty use in thelogging-industry, andsiniilaroperations, loutthe invention is-of general application tomany different kinds-ofpowertransmission; the presentembodiment being illustrated by way ofexamplea'nd not as a limitation of the' invention.

1 also-wish itto-be" understood that I do not desire to he limited" tothe exact details of construction-shown and-described; for obviousmodi-' limited rotation' on said'bra'cket; cam slots for said followersinsaid quadrant; each slot having one end portion disposed in a planeperpendicular to the rotational axis of the quadrant to hold itsshifting lever stationary in neutral position and an opposite endportion angularly disposed to move its shifting lever, the angular endsof the two slots 'being oppositely directed around the quadrant to moveonly one shifting lever at a time whentherqu'a'drantis rotatediand'saidslots being relatively positioned to hold" both shifting lovers inneutral position when the cam followers are engaged in central portionsof the slots, a

handlefor rotating said quadrant, and a resilient indexin device on thequadrant to hold central and endportions of 'the slots engaged with saidfollowers:

2. In a power transmission for driving winch drums and: the like, lowand high speed shifter members in the transmission for changing thedriving ratio, each of said members having driving and neutralpositions, a control pedestal having a;-shifter quadrant mountedforlimitedrotation, a handle on said quadrant,- resilient indexinglmeans toholtrthequadrant inacentral neutral position and1owand highend positionsof."v

. rotative movement. a mirror cam slots in said quadrant, low and highshifting levers mounted: intermediate their ends' on 'said' pedestaL.cam followers on: the upper ends; of: said levers: en-- gaged in saidcam slots, operatinglinks for: said: shifter members; connected with:the. lower ends of said levers, and: ai-leng-th: adjustment ineachof'saidilinks, the camslot for thelow speed:shift-- ing leverhaving: an endcandicentralportion to" hold: said low speed-'shiiterf-memberz in neutral" position when theiquadrant is':'in: highand neutral positions; and having; an opposite: angular. end portion tomove: said: shifter member. todrivingt position when the 'qua'drant ismoved to low: p'osi-- tion, and the-cam slotfor":theihigh'speedishiiting lever. having anend: and central'portion tohold said high speed shifter member in neutra1'position when thequadrant is in low and neutral posi tions and having anopposite'angular'end-portion to: move said shifter member to driving.position when the quadrant is. moved to high position. ADOLPH ZWALD.-

-REFERENCES- CITED The following. references are of record in the" fileof this" patent:

UNITED STATES=PATENTS Number Name- Date 6913968 Paine Jan. 28, 1902"114155239 Hupp- May-9, 1922 1 ,552,873 Csbbrn' Sept. 8, 1925 1,710,002Pearson Apr. 23, 1929" 118192389" Gtz Aug. 18, 1931 2,170,982 E'llinwood-iA ugi 29, 1939 2,258,475 Sinclair" Oct. 7, 1941 2,261,432 Cooke NOV.4, 194-1

